Paul Bateson was kind enough to post his photos of the 9117 charter in his STO Flickr album:
https://www.flickr.com/photos/buses-international/36200142040/in/album-72157635415663840/
https://www.flickr.com/photos/buses-international/35760949814/in/album-72157635415663840/
As for why the MCI logo was white, it looks as if the STO simply painted it white along with the rest of the front end cap.

According to this presentation on Councillor Egli's website, the 55 will travel on the Queensway between Carling and Bayshore. There's no detailed info about Stage 2-related route changes yet.
http://keithegli.ca/wp-content/uploads/2017/06/OttawaWest_2018_Route_Network-FINAL.pdf
As for other communities, Councillor Fleury is the only other councillor on whose website I've been able to find a presentation about post-LRT bus route changes (starting on page 24):
https://s3.amazonaws.com/mathieufleury/2017/06/Ready-for-Rail-Presentation-OC-Transpo-East-of-the-Rideau-Transit-Forum-FINAL.pdf

According to the maps posted on Councillor Leiper's website, route 10 (formerly route 4) will be extended to downtown Gatineau via Lyon Station and the Portage Bridge at on end, and be extended to Billings Bridge and Hurdman Stations at the other. For west-end riders, route 85 will be redirected to Gatineau via Pimisi Station and the Chaudiere Bridge.
In addition, route 61, 63, and 75 (former 95) will provide peak-period service along the Chaudiere Bridge, while the STO will serve Lyon Station.
http://www.kitchissippiward.ca/sites/default/files/Central_2018_Route_Network FINAL.pdf (page 3)

Actually, fifteen 1979 buses were converted to propane in 1984 as part of a federal-provincial study on alternative fuels. I've mentioned the propane Fishbowls a few times in this thread, and @MCIBUS posted some photos he took of them at the time:

City workers finally installed the crossover yesterday, though there are still plastic bags over the lights and signs. It is located between Appleford Street and the CSIS/CSEC shipping & receiving access road:
https://www.google.com/maps/@45.4411468,-75.6122444,20.75z

The 1997 Orion V buses were delivered with the white panels, but they were quickly painted grey and the front end painted entirely in red. I never managed to get a photo of the Orion V buses with the white around the bottom, and this is the earliest photo I took of a 1997/1998 Orion V (taken at Confederation Square in Feb. 1999):

7930 also had a ground-level tailpipe and two flat white plates next to the rear window similar to the BC Transit hillclimbers, at least back in the 1990s. I thought it looked neat and a little like the rear window of a TDH-5301.